Lightning-arrester.



Nol 848,045.

PATENTED MAR. 26, 1907. J. H. PBARSON. LIGHTNING ARRESTBR.

APPLICATION FILED JAN. 9, 1906.

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JAMES H. PEARs'oN, or BLooMriELD, INDIANA.

LIGHTNING-ARRESTER- Specification of Letters Patent.

Patented March 26, 1907.

,Application file-.l January 9, 1906.I Serial No. 295.291.

.To all whom 15m/ay concern:

Be it known that I, JAMES H'PEARsoN, a citizen of the United States, residing at Bloomfield, in the county of Greene and State of `Indiana, have invented certain new and' there is a grouiul-teiminal, so that any overl load or excessive current `will expand the columns of mercury in the passages or tubes and effect a contact between the saine and the groumil-terminal to carry oil the excessive current. v i

the merits thereof, and also to acquire a knowledge of the details of construction of the means for effecting the result, reference is to be hadto the fo-llowing description and accompaiiying drawings, in which- Figure l' ai perspective view of my invention. Fig. 2 is a vertical section thereof. Fig. 3 is a horizontal section.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters. Y

Referring to the drawing, the numeral 1 designates a block, which is preferably of porcelain or similar non-conducting material. The block 1 is provided with two longitudinal passages 2, each of which opens atboth ends into an enlargement or chamber 3. Into each chamber 3 there extends aline-terminal 4, provided with any desired form of bindingscrew for the line-wires 5.

6 designates a ground-plate, which in the present instance ispermanently attached t'o one end of the block 1 and is provided with two terminals 7, extending into the adjacent chambers 3. The ground-plate 6 is provided with a binding-screw for the ground-wire 8.

9 designates screws or similar fastening means by which the block 1 may be secured to any stationary. part and at the proper convenient location.

The passages 2 and chambers 3 in theblock 1 are designed to contain a predetermined amount of mercury or `similar conducting and expansible Ine-- dium 10, and theamount of said medium 1s so regulated or determined as to leave under normal conditions an air-space 11 between the'gnound-terininal 7 and the said conductingl` medium, as indicated in the drawings.

n the practical operation of the device any slight excessive current introduced into the maincircuit will by its heat expand the mercury 10, and thereby eliminate the airspaces 11 between the mercury and the ground-terminals 7, and therebyground the circuit and absorb or carry off the overload. Hence the sensitive mechanisms of the tele- Aphone or other device to which my improved block is connected will be protected from any excessive or overload current at all times. Any excessive current or high voltage, such as would occur from lightning, would so act on the mercury 10 that it would violently expand the same and notonly effect a contact between the ground-terminals and the mer- AFor a full' description of the invention and cury, butbreak the columns of mercury at different points by the violent expansion.

From the foregoing description, in connection with the accompanying drawings, it will be seen that TI have provided an improved construction of lightning-arrester or similar device which embodies two mercury columns designed to be introduced in an electric circuit` and so arranged in connection' with a ground-terminal that any excessive current or overload will short-circuit or ground the circuit and protect the included parts from injury. e

Having thus described the invention,what is claimed as iiew is 1. A device of the character described,

comprising a block of insulating material provided with line-terminals and columns of expansible conducting media connecting the same, and ground-terininals secured to said block, said `ground-terminals being in com- IOO munication with the said columns and norchambers communicating therewith at both*A ends, line-terminals secured to said block and extending into said chambers, columns `of ex-v pansible conducting media in said passages and chambers, and -ground-terminals extendmg into said chambers and normally spaced from the columns of mercury therein.

A device of the character described,v

comprising ablock of insulating material pro-- vided with two capillary passages enlarged at both ends' whereby to forni four chambers, columns of mercury in said passages and chambers, line-terminals secured to said block and each extending into one of said chambers in contact with the mercury therein, and aground-plate secured to thetop of JAuEsH. PEARsoN. [L 8.]

Wiitnesses: i

JOHN M. GRAY, LON ALLEN. 

